The Wisconsin Department of Natural Resources says the hot weather has spurred the growth of blue-green algae blooms in lakes, streams and ponds. The blooms are toxic to people and animals and advise that you avoid areas where a scum or mat of algae is present.
People exposed to blue-green algae may experience rashes, gastrointestinal ailments, and respiratory irritation. People experiencing symptoms should contact their health care provider or the Poison Control Center at 1-800-222-1222. People are also encouraged to report potential algae-related illnesses to the Wisconsin Department of Health Services.
DNR veterinarian Dr. Lindsey Long says “Animals have a higher risk from dying after exposure to blue-green algae toxins because they may ingest large amounts of toxins from drinking lake, pond, or river water or licking algae from their fur. Symptoms can include abnormal sluggishness, loss of appetite, vomiting, diarrhea or even seizures. If your animal shows any of these symptoms contact your veterinarian immediately.”
According to the DNR: Blue-green algae, technically known as cyanobacteria, are microscopic organisms that are naturally present in Wisconsin lakes, streams and ponds at low levels. When conditions are favorable, usually in summer, the number of algae can increase dramatically, forming pea-soup blooms and scums on the water surface. Their populations peak from July to September.
Cyanobacteria blooms can develop in surface waters with high concentrations of nutrients, particularly phosphorus. Blooms tend to grow when there is a lot of sunlight, water temperatures are high, and there is little wind. Wind can push blooms to the windward side of lakes.
All blue-green algae contain compounds that can cause rashes or gastrointestinal illness with ingestion. Additionally, some algal species produce toxins that, when ingested, can harm the neurological systems or liver of people, pets, livestock and wildlife. Not all cyanobacteria produce toxins, but the presence of blue-green algae blooms in lakes, ponds, or rivers is an indication that the public can use to determine a potential hazard.